题目内容
阅读下列短文, 从所给的四个选项中, 选出最佳答案。You believe that all liquids flow downwards, don't you? Try the following experiment and you will think again.
Get a bottle filled with the gas helium (氦) and plug it up. Cool it to a very low temperature. The gas will form a liquid. Now pull out the plug at the top. You will be astonished to see the liquid immediately escape by moving up the inner side of the bottle and then down the outer side. If you want to fill a bottle with liquid helium, simply stand it in the liquid. The liquid will start climbing into the bottle by itself until the levels outside and inside are the same.
So, the first requisite for a scientist is: DO NOT TAKE ANYTHING FOR GRANTED.
(1) What is the major difference between liquid helium and other liquids? [ ] A. It becomes active at a very low temperature. B. It can escape from a closed bottle. C. It moves upwards as well as downwards. D. It moves upwards instead of downwards. (2) What will happen if you pull out the plug of the small bottle which is inside the big jar in Figure 1? Which picture in Figure 2 represents (表示) the result? [ ] (3) What is the main purpose of the passage? [ ] A. To teach people a lesson in chemistry. B. To tell people how to do an experiment. C. To interest people in an unusual scientific fact. D. To encourage people to ask for facts to support correct statement (陈述).